1. Field of the Invention
The present invention generally relates to temperature control, and more particularly, to a cost-effective temperature control apparatus including a variable-speed fan that is suitable for use in devices such as consumer electronics devices having different thermal characteristics, and a method for controlling temperature using such a device.
2. Background Information
Devices such as consumer electronic devices often require a temperature control mechanism such as a fan to prevent damage from excessive heat. At present, there are various different types of fans that may be used by such devices for temperature control. One such type of fan may be controlled by a thermistor. Thermistor-controlled fans can be a cost-effective option for temperature control in certain applications, but are disadvantageous in that the relationship between fan speed and temperature is fixed by the thermistor. Accordingly, thermistor-controlled fans may be unsuitable for certain applications. For example, thermistor-controlled fans may be unsuitable for applications in which the fan's orientation in a final device may vary (e.g., from model to model), and thereby require the relationship between fan speed and temperature to be modified in order to compensate for different thermal characteristics.
Another type of fan can be controlled by pulse width modulation (PWM). In short, PWM-controlled fans use the relative width of pulses in a train of on and off pulses to control the amount of power applied to the fan motor, and thereby control its rotating speed. Currently available PWM-controlled fans tend to be relatively expensive since they may utilize an expensive high-current transistor driven by the fan's operating power for receiving the pulses that control the fan's rotating speed. As a result, currently-available PWM-controlled fans may be unduly expensive for certain applications, particularly those applications where cost is a critical consideration.
Accordingly, there is a need for a cost-effective temperature control apparatus including a variable-speed fan that avoids the foregoing deficiencies, and is suitable for use in devices such as consumer electronics devices having different thermal characteristics. The present invention addresses these and/or other issues.